At the present day, an unsaturated nitrile which is generally available commercially is mainly produced industrially by the vapor-phase catalytic ammoxidation reaction of olefin, ammonia, and oxygen. On the other hand, in recent years, a method for subjecting an alkane such as propane or isobutane as a feedstock in place of the olefin to a vapor-phase catalytic ammoxidation reaction to produce a corresponding unsaturated nitrile has attracted much attention. Various catalysts used in the case have also been proposed.
Patent Literature 1 describes a method for producing a catalyst to be used for the vapor-phase catalytic oxidation or vapor-phase catalytic ammoxidation of propane or isobutane. The method for producing a catalyst described in Patent Literature 1 comprises a step of drying and calcining a raw material blending liquid obtained by the following steps (1) to (4):
a step (1) of preparing an aqueous mixed liquid comprising Mo, V and Sb;
a step (2) of adding silica sol and hydrogen peroxide water to the aqueous mixed liquid obtained in the above step (1);
a step (3) of mixing the solution obtained in the above step (2) with an aqueous solution comprising Nb, dicarboxylic acid and hydrogen peroxide water, and a W-containing compound; and
a step (4) of adding a powder silica-containing suspension liquid to the solution obtained in the above step (3).